JP2785211B2 - Color television camera device - Google Patents

Description

The present invention relates to a color television camera device for forming and outputting a composite video signal by digital signal processing for an image pickup output.

B. Summary of the Invention The present invention relates to a color television camera device for forming and outputting a composite video signal by digital signal processing with respect to an imaging output obtained by an imaging unit.
A 2fs rate digital luminance signal is formed from the digital three-primary color image pickup signal, a fs rate digital color difference signal is formed, and the fs rate modulated color difference signal modulated by the digital color difference signal is converted to the 2fs rate to obtain the 2fs rate.
By mixing with the digital luminance signal of fs rate,
By forming a 2fs rate digital composite video signal and converting this 2fs rate digital composite video signal into an analog signal, a high resolution composite video signal can be obtained without harmonic distortion of the color subcarrier. It was done.

C Conventional technology Conventionally, a charge coupled device (CCD) has been used.
e) In a solid-state imaging device using a solid-state image sensor having a discrete picture element structure formed by e.g. as an imaging unit, the solid-state image sensor itself is a sampling system. It is known that aliasing components from the spatial sampling frequency fs are mixed.

Further, in a color television camera device that captures a color image, a two-plate solid-state image sensor that captures a three-primary-color image using a solid-state image sensor provided with a color coding filter for red and blue pixels of a solid-state image sensor for capturing a green image. 2. Description of the Related Art An image pickup device and a multi-plate solid-state image pickup device such as a three-plate type solid-state image pickup device for picking up three primary color images by individual solid-state image sensors have been put to practical use.

Furthermore, conventionally, as a technique for improving the resolution in the multi-plate solid-state imaging device, a solid-state image sensor for capturing a green image is used for capturing a red image by a half of a spatial sampling period of a pixel. A so-called space picture element shifting method in which a solid-state image sensor for picking up a blue image is staggered is known. By employing this spatial picture element shifting method, a high resolution exceeding the limit of the number of pixels of the solid-state image sensor can be realized in the analog output multi-plate fixed imaging device.

Further, in a color television camera device that performs digital signal processing on an image pickup output, a color sub-carrier frequency f _sc
Digital signal processing is performed at a clock rate fs (fs ≒ 4f _sc ) which is about four times that of FIG. 9, and as shown in FIG. 9 so as not to be affected by harmonic components of the color subcarrier frequency f _sc . , the output band of the composite video signal CS obtained by mixing a modulated color difference signal MOD.C the luminance signal Y is limited to less than or equal to the frequency of the 2f _sc.

D Problems to be Solved by the Invention Incidentally, in order to improve the image quality of a television image, a wider band of a television signal is being promoted. However, as described above, in a color television camera device that performs digital signal processing on an image pickup output by a solid-state image sensor having a discrete picture element structure such as a CCD, the output band of the composite video signal is expanded to a frequency of 2 _fsc or more. In this case, the color signal component is unnecessarily suppressed, or harmonic distortion is generated in the color subcarrier, thereby deteriorating the image quality.

Accordingly, the present invention has been made in view of the above-described problems, and in a color television camera apparatus that performs digital signal processing on an image pickup output by a solid-state image sensor having a discrete picture element structure such as a CCD, a color signal component becomes unnecessary. It is an object of the present invention to obtain a high-resolution composite video signal without being suppressed or accompanied by harmonic distortion of a color subcarrier.

E. Means for Solving the Problems In order to achieve the above object, a color television camera apparatus according to the present invention comprises: an image signal generating means for generating a digital three-primary color image signal having a 2 fs rate; A luminance signal forming means for forming a digital luminance signal at a rate of 2 fs from the three primary color image pickup signals;
color difference signal forming means for forming a fs rate digital color difference signal from an s rate digital three primary color image pickup signal;
a modulating means for modulating a digital color difference signal having an fs rate;
Rate conversion means for converting the modulation type difference signal by the modulation means to a 2fs rate, and composite video signal formation means for forming a 2fs rate digital composite video signal from the 2fs rate digital luminance signal and the 2fs rate modulated color difference signal; And a digital-to-analog conversion means for converting the digital composite video signal having the 2fs rate into an analog signal.

F Function In the color television camera device according to the present invention, the image signal generating means generates a digital three primary color image signal at a 2fs rate, and outputs the digital three primary color image signal at a 2fs rate to a luminance signal forming means and a color difference signal forming means. And give to.

For example, the imaging signal generating means may include a solid-state image sensor for recording a recorded image and a solid-state image sensor for capturing a red image and a solid-state image sensor for capturing a blue image.
The imaging unit arranged spatially shifted by 2 and the three primary color imaging output signals read out at a sampling rate of fs from each of the solid-state image sensors are converted to the sampling rate fs.
Analog digitizing at a clock rate equal to
It can be constituted by digital conversion means and rate conversion means for converting the digital three primary color image pickup output signal obtained by the analog / digital conversion means into a digital three primary color image pickup output signal of 2 fs rate by interpolation processing.

The luminance signal forming means forms a digital luminance signal of a 2fs rate from the digital primary color image pickup signal of a 2fs rate, and supplies the digital luminance signal of the 2fs rate to the composite video signal forming means.

Further, the color-difference signal forming means down-samples the 2 fs digital three-primary-color image signal by the image signal generating means to a fs generator via a pre-filter having at least one zero at a frequency of fs. , To form the digital color difference signal of the fs
A rate digital chrominance signal is provided to the modulating means.

The modulating means modulates the color subcarrier with the digital color difference signal having the fs rate, and supplies a modulated color signal having the fs rate to the rate converting means.

The rate conversion means converts the modulated color difference signal from the modulation means to a 2fs rate, and provides the 2fs modulated color difference signal to the composite video signal forming means.

This rate conversion means is constituted by a digital filter which has a filter characteristic which passes the color _subcarrier frequency _fsc component and blocks the fs- _fsc frequency component.
Furthermore, the rate converting means, differential coefficient is substantially 0 at the color sub-carrier frequency f _sc, at least near the frequency of fs-f _sc 1
It can be constituted by a digital filter exhibiting a filter characteristic having zero points.

Further, the composite video signal forming means is
A 2 fs rate digital composite video signal is formed from the 2 fs rate digital luminance signal and the 2 fs rate modulated color difference signal, and the 2 fs rate digital composite video signal is supplied to digital / analog conversion means.

The digital-to-analog conversion means includes:
It converts a 2fs rate digital composite video signal into an analog signal and outputs an analog composite video signal.

G. Embodiment Hereinafter, an embodiment of the color television camera device according to the present invention will be described in detail with reference to the drawings.

The color television camera device according to the present invention has a first
It is configured as shown in the figure.

The color television camera device shown in FIG.
Decomposed into three primary color light components imaging light L _i is incident through the optical low-pass filter (2) from the image pickup lens (1) by the color separation prism (3), three pieces of the CCD images of the three primary colors images of the object image The present invention is applied to a three-panel solid-state imaging device that captures images using sensors (4R), (4G), and (4B), and is an NTSC color television camera device.

In this embodiment, the three CCD image sensors (4R), (4G), and (4B) constituting the image pickup unit of the color television camera device adopt a spatial picture element shifting method, and As shown in the figure, a CCD image sensor (4R) for capturing a red image and a blue image for a half of the spatial sampling period τ _s of a picture element with respect to a CCD image sensor (4G) for capturing a green image. ), (4B) are shifted. Then, the above three CCD image sensors (4
R), (4G), and (4B) are driven by a CCD drive circuit (not shown), and the imaging charge of each picture element is converted to the color _subcarrier frequency _fsc of 4
It is read by a read clock having a double sampling frequency fs (fs = 4f _sc ).

The three CCD image sensors (4R), (4G), and (4B) adopting the spatial picture element shifting method described above use the CCD image sensor (4G) for capturing the green image and the red image sensor for the three primary color images of the subject image. For imaging and blue imaging
CCD image sensor (4R), spatial sampling position and is shifted by τ _2/2 (4B). Thus, each of the CCD image sensor (4R), shown in (4G), three primary color image pickup output signal by _{(4B) S R *, S} G *, S B * is the signal spectrum of FIG. 3 (A) As described above, the component of the sampling frequency f _s of the green image pickup output signal _{SG *} by the CCD image sensor (4G) and each of the CCD image sensors (4G)
R) and (4B), the components of each of the sampling frequencies fs of the red imaging output signal SR _* and the blue imaging output signal SB _* have phases opposite to each other.

Then, the 4f _sc becomes the sampling frequency fs the CCD image sensor by reading clock (4R), (4
G) and (4B) read out image pickup signals S _{R *} and S
_{G *} and SB _* are the buffer amplifier (5R) and (5
G) and (5B) are supplied to analog / digital (A / D) converters (6R), (6G), and (6B).

These A / D converters (6R), (6G), and (6B) provide a clock rate equal to the sampling rate fs of each of the imaging output signals SR _* , _{SG *} , and SB _* , that is, the CCD image sensor ( 4R), is given by (4G), (4B) the same fs = 4f _sc clock frequency fs timing generator clock is not shown in the read clock. Then, the A / D converter (6R), (6G), (6B) , said each of the image pickup output signals S _{R *,} S _{G *,} the S _{B *} by directly digitized at the clock rate fs of the 4f _sc , And the respective digital color signals D _{R *} , D _{G *} , D _{B *} having the same output spectrum as the spectrum shown in FIG. 3 (A) of the respective imaging output signals S _{R *} , S _{G *} , S _{B *} . To form

The A / D converter (6R), (6G), the digital chrominance signals _{D R *} obtained by _{(6B), D G *,} D B * , the interpolation processing unit (7R), (2G), (7B ).

These interpolation processing units (7R), (7G), and (7B)
Each imaging output signals S _R rate _*, S _{G *,} S _B, respectively, by applying an interpolation process to the _*, twice the clock rate each digital color signals D of 2fs of the clock rate fs
Form _{R **} , _{DG **} , _{DB **} .

That is, in this color television camera device,
An imaging unit using three CCD image sensors (4R), (4G), and (4B) that adopt the spatial pixel shifting method, and the CCD
Each imaging output signal SR _* , S read from the image sensor (4R), (4G), (4B) at a sampling rate of fs
An analog / digital (A / D) converter (6R), (6G), (6B) for digitizing _{G *} , SB _* at a fs rate equal to the sampling rate fs, and the analog / digital (A / D) ) converter (6R), (6G), ( each digital color signals obtained by _{6B) D R *, D R} *, 2 times the 2fs of the fs rate by subjecting each interpolation processing D _{R *}
Each digital color signal of the rate _{DR **} , _{DR **} , _{DR **}
Each of the digital color signals D as three digital primary color image pickup output signals having a frequency distribution of 2 fs as shown in FIG. 3B by interpolation processing units (7R), (7G), and (7B) for forming _{R **, D G **,} image signal generating means for outputting a _{D B **} is constructed.

Wherein each CCD image sensor using the above spatial pixel shifting method (4R), (4G), 3 primary color image pickup output signal by _{(4B) S R *, S} G *, S B * , as described above Since the phase of the green imaging output signal _{SG * and} the respective phases of the red imaging output signal SR _* and the blue imaging output signal SB _* are shifted by π,
Although these cannot be calculated directly, the interpolation processing unit (7R),
By performing the interpolation processing according to (7G) and (7B), each digital color signal DR _** , DG _** , D
Since the phases are aligned by setting _{B **} , process processing and the like can be performed by digital arithmetic processing at the subsequent stage.

In addition, the above-mentioned imaging signal generating means requires the above-described interpolation processing and the like by using a solid-state image sensor having a sufficiently large number of picture elements capable of securing a high resolution without adopting the spatial picture element shifting method in the imaging section. No, 2fs from A / D conversion means
Alternatively, a digital primary color image pickup output signal of a rate may be generated.

The interpolation processing unit constituting the image pickup signal generating means (7R), (7G), the digital color signals of 2fs rate obtained by _{(7B) D R **, D} G **, D B ** is , And a matrix circuit (8).

Said matrix circuit (8), each digital color signals D _{R * *} the 2fs _rate, D _{G **,} by matrix calculation processing for D _{B **,} as shown in the FIG. 3 (C), 2fs rate of the digital luminance signal D _{Y **} and fs-rate of the respective digital color difference signal D _{C1 *,} to form the D _{C2 *.}

In forming the digital color difference signals _{DC1 *} and DC2 _{* at} the fs clock rate in the matrix circuit (8), the digital color signals DR _** and D at the 2fs rate are used.
_{G **,} for _{D B **,} at least the said respective digital color signal through a pre-filter having a zero point one to the frequency of _{fs D R **, D G **} , to downsample _{D B **} By the above, each digital color difference signal D of the fs rate is
_{C1 *} and D _{C2 *} are formed.

The matrix circuit (8) supplies the digital luminance signal DY _** at the 2fs rate to the addition circuit (14) via the delay circuit (9) and outputs the digital luminance signal DY _** from the signal output terminal (21). The matrix circuit (8)
, Each digital color signals D of the 2fs consisting clock rate _{R **,} D _{G **,} D each digital color difference signal D of the fs rate formed by the _{B **} downsampling
_{C1 *} and _{C2 *} are supplied to the modulation circuit (12) via the low-pass filters (10) and (11).

The modulation circuit (12) is a digital color difference signal having a signal spectrum as shown in FIG. 3D supplied from the matrix circuit (8) through the low-pass filters (10) and (11). A modulation process for orthogonally biaxially modulating the color subcarrier is performed by using _{DC1 *} and _{DC2 *} .

The modulated color difference signal MOD.C _{* at the} fs rate obtained by the modulation circuit (11) has a frequency distribution as shown in FIG. 3 (E) including odd harmonics of the frequency f _sc of the color subcarrier. This corresponds to the modulated color signal. This modulation circuit (11)
The modulated color difference signal MOD.C _* of the fs rate obtained by the above is supplied to the addition circuit (14) via the rate conversion circuit (13) and is output from the signal output terminal (23).

Here, the modulation circuit (11) modulates the chrominance signal of fs rate obtained by MOD.C _* is because it contains odd harmonics of the color sub-carrier frequency f _sc, as described above, 3f _sc in this state Will affect the composite video signal.

Therefore, the rate conversion circuit (13) converts the modulated color difference signal MOD. MOD of the fs rate obtained by the modulation circuit (11).
For C _*, the third filter characteristic shown in (F) of FIG due performs digital filtering for extracting a frequency component of the frequency components and 7f _sc of f _sc, 2f _s rate corresponding to the frequency of 8f _sc first A modulated color difference signal MOD.C _** having a frequency distribution as shown in FIG. 3 (G) is formed. The rate conversion circuit (13) is constituted by a digital filter having a filter characteristic that passes the color _subcarrier frequency _fsc component and blocks the passage of the fs- _fsc frequency component. Digital filter used in the rate conversion circuit (13) is substantially zero differential coefficient at a frequency of f _sc, if exhibits a filter specified having at least one zero configuration near the frequency of fs-f _sc Well, in the case of the NTSC system like the color television camera device of this embodiment, for example, With the transfer function H ₁ (z) given by the first equation, the filter function shown in FIG. Transfer functions H _A (z), H _B given by the second to fifth equations of
(Z), H _C (z) and H _D (z) are used which exhibit the respective filter characteristics shown in FIG.

The addition circuit (14) is obtained by the rate conversion circuit (13) from the matrix circuit (8) to the 2fs rate digital luminance signal DY _** supplied via the delay circuit (9). Modulated color difference signal MOD.C at 2fs rate
By adding and combining _** , a digital composite video signal D _{CS **} having a frequency distribution of 2 fs as shown in FIG. 3H is formed. The 2fs rate digital composite video signal D _{CS **} is supplied to a digital / analog (D / A) conversion circuit (15).

The delay circuit (9) is necessary for forming the 2fs-rate modulated color difference signal MOD.C _** from the digital color difference signals _{DC1 *} and DC2 _* output from the matrix circuit (8). A delay amount corresponding to the processing time is given to the digital luminance signal _{DY **} .

The D / A conversion circuit (15) converts the 2fs rate digital composite video signal DCS _** into an analog signal,
An NTSC analog composite video signal CS is passed through a post-filter (16) having a low-pass filter characteristic as shown in FIG. 3 (I) which passes a low-frequency component lower than approximately 4f _SC, that is, fs. Output from the output terminal (23).

Since the analog composite video signal CS output from the signal output terminal (23) is an analog version of the digital composite video signal D _{CS **} at the 2fs rate, as shown in (J) of FIG. In the above 4f
The band of the luminance signal Y is expanded to the _SC frequency, that is, fs,
High resolution images can be provided.

Also, 2fs obtained by the rate conversion circuit (13)
Rate modulated chrominance signals MOD.C _** passes through the color sub-carrier frequency f _SC components as described above, by interpolation by a digital filter exhibiting a filter characteristic for blocking the passage of frequency components of fs-f _SC Since it is formed, it does not include the frequency component of 3f _SC as shown in FIG. 3 (G). Therefore, the 2fs rate modulated color difference signal MOD.C _** is converted to the 2fs rate digital luminance signal D.
_{Y **} in synthesis by adding the analog composite video signal CS digital composite video signal D _{CS **} formed by analog of the 2fs rate never accompanied by harmonic distortion of the color subcarrier.

Here, in the above embodiment, the present invention is applied to a color television camera device of the NTSC system, and 2f where fs = 4f _SC
The digital processing of the clock rate of the s i.e. 8f _SC to form a digital composite video signal D _{CS **} the 2fs rate, by an analog of the digital composite video signal D _{CS **,} color harmonic distortion of subcarriers Although the analog composite video signal CS capable of providing a high-resolution image without accompanying the same is formed, in the color television camera device according to the present invention, the sampling frequency fs is the color carrier frequency f _SC
The frequency does not need to be an integer multiple of. Therefore, according to the present invention, for example, as shown in FIG. 6, a signal spectrum corresponding to the various signal spectra shown in FIG. The present invention can also be applied to a television camera device.

That is, in the color television camera device of the PAL system, _* each of the image pickup output signals read from the CCD image sensor which employs the spatial pixel shifting method in the read clock of the sampling frequency _{fs S R, S G *,} S B * is ,
It has a signal spectrum as shown in FIG.

In the above PAL color television camera device,
The sampling frequency fs is not a 4-fold color sub-carrier frequency f _SC in the PAL system is set to 908 times and 944 times, etc. of the horizontal scanning frequency f _H, for example in the PAL system.

Each of the imaging output signals SR _* , _{SG *} , SB _* is digitized at the same fs rate as the sampling frequency fs,
By the digital interpolation processing, each digital color signal D of 2 fs rate of the signal spectrum shown in FIG.
It is converted to _{R **} , _{DG **} , _{DB **} .

Each digital color signal DR _** , D of the above 2fs rate
_{From G **} and DB _** by matrix operation processing
2fs of the signal spectrum as shown in FIG.
Rate of the digital luminance signal D _{Y * *} and fs rate for each digital color difference signal D _{C1 *,} D _{C2 *} is formed.

Each digital color difference signal D _{C1 *} , D at the above fs rate
_{C2 *} is obtained by extracting a frequency component as shown in FIG. 6 (D) by a chroma filter and orthogonally biaxially modulating the chrominance subcarrier by a PAL modulating means. The fs rate modulated color difference signal MOD.C _* having the signal spectrum as shown is formed.

The modulated color difference signal MOD.C _* having the fs rate is converted into a sixth color by digital interpolation using a digital filter having a filter characteristic as shown in FIG. 6F which blocks the passage of the frequency component of fs-f _SC . The signal is converted into a modulated color difference signal MOD.C _** of a 2fs rate of the signal spectrum as shown in FIG.

By adding and synthesizing the modulated color difference signal MOD.C _** at the 2fs rate and the digital luminance signal at the 2fs rate, 2f of the signal spectrum as shown in FIG.
s-rate digital composite video signal D _{CS **}
To form

The digital composite video signal D _{CS **} having a rate of 2 fs is converted into an analog signal by a digital-to-analog converting means, and a low-pass filter having a low-pass filter characteristic as shown in FIG. A PAL analog composite that provides a high-resolution image in which the band of the luminance signal Y has been expanded to the above-mentioned fs without including aliasing components as shown in FIG. Video signal CS
Can be obtained.

Here, when the present invention is applied to a PAL color television camera device, the fs rate modulated color difference signal MOD.
Digital filter for performing an interpolation process as a rate converting means for converting the C _* of the the modulated color difference signals MOD.C _** 2fs rate, as for example, fs = 908 f _H, By the sixth equation by the transfer function given H _a of (z) and which exhibits the filter characteristics shown in FIG. 7, as fs = 944f _H, It can be used for exhibiting the filter characteristics f _b of the seventh expression transfer function given by H _b of (z) shown in Figure 8.

H As described above, in the color television camera device according to the present invention, the imaging signal generating means generates a digital 3 primary color imaging signal at a 2 fs rate, and converts the 2 fs digital 3 primary color imaging signal into a luminance signal. Since the luminance signal forming means and the color difference signal forming means are provided to the forming means and the color difference signal forming means, the luminance signal forming means and the color difference signal forming means can form a digital luminance signal and a digital color difference signal from the 2 fs rate digital three primary color image pickup signals.

For example, the imaging signal generating means may include a solid-state image sensor for recording a recorded image and a solid-state image sensor for capturing a red image and a solid-state image sensor for capturing a blue image.
The resolution is increased by the so-called spatial picture element shifting method by using the imaging units arranged spatially shifted by two, and the three primary color imaging output signals read out at the sampling rate of fs from the solid-state image sensors are set to the sampling rate fs. The 3 fs primary color imaging output signal obtained by the analog / digital conversion means for digitizing at the same clock rate is converted into a 3 fs digital primary color imaging output of 2 fs rate by interpolation processing in the rate conversion, whereby the 2 fs rate of the phase is aligned. A digital three primary color image pickup output signal can be output.

The luminance signal forming means can form a 2fs rate wide band digital luminance signal from the 2fs rate digital primary color image pickup signal.

Further, the color difference signal forming means down-samples the 2 fs digital three-primary color image signal by the image signal generating means to a fs rate through a pre-filter having at least one zero at a frequency of fs. An fs rate digital color difference signal can be formed.

The modulated color signal of the fs rate obtained by the modulation means to which the digital color difference signal of the 2fs rate is supplied from the color difference signal forming means is converted into a modulated color difference signal of the 2fs rate by a rate converter, and the composite video signal The composite video signal forming means, when supplied to the forming means, forms a 2fs rate digital composite video signal from the 2fs rate digital luminance signal and the 2fs rate modulated color difference signal.

Further, the rate conversion means passes through the color sub-carrier frequency f _SC component, the digital filter that exhibits a filter characteristic for blocking the passage of frequency components of fs-f _SC, for example, the derivative in the color sub-carrier frequency f _SC Is approximately 0, and has a filter characteristic having a filter characteristic having at least one zero near the frequency of fs−f _SC ,
The effect on the composite video signal by the harmonics of the color subcarrier can be removed.

Therefore, in the color television camera device according to the present invention, the composite video signal forming means forms a digital composite video signal of 2fs rate from the modulated color difference signal of 2fs rate digital luminance signal of 2fs rate. By converting a digital composite video signal into an analog signal by a digital-to-analog converter, an analog composite video signal that provides a high-resolution image whose luminance signal band is expanded up to the above fs without accompanying harmonic distortion of the color subcarrier. Obtainable.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an NTSC type color television camera device to which the present invention is applied to a three-plate solid-state imaging device, and FIG. 2 shows the arrangement of each CCD image sensor in the color television camera device. FIG. 3 is a schematic diagram for explaining the operation of the color television camera device, and FIG. 4 is a characteristic diagram showing an example of characteristics of a digital filter for interpolation processing used in the NTSC color television camera device. The diagram and Fig. 5 are the same NTSC
Diagram showing another characteristic example of a digital filter for interpolation processing used in a color television camera device of a system,
FIG. 6 is a schematic diagram for explaining the operation of the PAL color television camera device to which the present invention is applied, and FIG. 7 is a characteristic example of an interpolation digital filter used in the PAL color television camera device. FIG. 8 is a characteristic diagram showing another characteristic example of a digital filter for interpolation processing used in the color television camera apparatus of the PAL system. FIG. 9 is a diagram showing a signal spectrum of a composite video signal formed by a conventional color television camera device. (4R), (4G), (4B) ... CCD image sensor (6R), (6G), (6B) ... A / D converter (6R), (6G), (6B) ... interpolation processing unit (8) Matrix circuit (12) Modulation circuit (13) Rate conversion circuit (14) Addition circuit (15) D / A converter (16) Post filter

Claims (5)

(57) [Claims] 1. An image signal generating means for generating a digital three-primary color image signal at a 2fs rate; a luminance signal forming means for forming a digital luminance signal at a 2fs rate from the digital three-primary color image signal at a 2fs rate; A color difference signal forming means for forming a digital color difference signal at the fs rate from the digital three primary color image pickup signals, a modulation means for modulating the digital color difference signal at the fs rate, and a rate for converting the modulated color difference signal by the modulation means to a 2 fs rate Converting means, composite video signal forming means for forming a 2fs rate digital composite video signal from the 2fs rate digital luminance signal and 2fs rate modulated color difference signal, and a digital / digital converter for converting the 2fs rate digital composite video signal into analog. A color television set having analog conversion means. Camera device. 2. The solid-state image sensor for recording a recorded image and a solid-state image sensor for capturing a red image and a solid-state image sensor for capturing a blue image.
An imaging unit arranged spatially shifted by 1/2, and an analog / digital converter for digitizing a three-primary-color imaging output signal read from each solid-state image sensor at a sampling rate of fs at a clock rate equal to the sampling rate fs. 2. The method according to claim 1, further comprising: conversion means; and rate conversion means for converting the digital three primary color image pickup output signal obtained by the analog / digital conversion means into a digital three primary color image pickup output signal having a 2 fs rate by interpolation. Item 7. The color television camera device according to Item 1. 3. The color-difference signal forming means down-samples the digital three-primary-color image signal of the 2fs rate by the image signal generating means to a fs rate via a prefilter having at least one zero at a frequency of fs. hand,
2. The color television camera device according to claim 1, wherein a digital color difference signal having an fs rate is formed. 4. The color conversion apparatus according to claim 1, wherein the rate conversion means includes a color subcarrier frequency f.
_2. The color television camera device according to claim 1, wherein the digital television camera device is constituted by a digital filter having a filter characteristic of passing an _sc component and blocking passage of a fs-f _sc frequency component. 5. The color conversion apparatus according to claim 1, wherein said rate conversion means includes a color subcarrier frequency f.
_5. A color television according to claim 4, wherein said digital television is constituted by a digital filter exhibiting a filter characteristic having a differential coefficient of approximately 0 in _sc and having at least one zero near a frequency of fs-f _sc. Camera device.